Risk-Averse Preventive Voltage Control of AC/DC Power Systems Including Wind Power Generation

Preventive voltage control (PVC) deals with the alert state of power systems, where the system operates in a stable regime but loading margin (LM) is insufficient or some operational constraints have been violated. Hence, the aim of PVC is to ensure a desired LM (i.e., restoration of normal operation state), while minimizing the corresponding control costs. This paper proposes a new stochastic PVC (SPVC) model for power systems operation, taking into account the uncertainties of wind power generation. The uncertainty of wind power generation is handled using a scenario-based modeling approach. The risk associated with each objective function (OF) is handled using conditional value at risk (CVaR). Voltage set-points of generation units, active power readjustment of predetermined generating units, load reduction of a predetermined load buses, along with the intermittent wind power generation, are employed as control measures in the proposed SPVC approach. Line-commutated converter high-voltage dc (LCC-HVDC) link constraints and doubly fed induction generators (DFIGs) capability curves are also considered in the proposed SPVC approach. To illustrate the effectiveness of the proposed approach, it is applied on the IEEE 39-bus test system. The obtained results substantiate the applicability of the proposed SPVC model to ensure secure operation of ac/dc power systems with high penetration of offshore wind farms.